How to calculate the main aortic graft-diameter for a chimney-graft

BACKGROUND: The aim of this paper was to present a mathematical model to calculate the required main aortic graft-diameter for parallel chimney-grafts.

METHODS: Geometric approximation model, developed to allow for a standardized calculation of the main aortic graft-diameter determined by the aortic diameter and the diameter of the chimney-graft.

RESULTS: We propose a mathematical formula using circular segments of the aorta and the chimney-graft and provide a table with recommended main aortic graft-diameters for single chimney-grafts of 6 and 8 mm.

CONCLUSION: Geometric approximation can be used to calculate the required main aortic graft-diameter. For parallel running chimney-grafts a significant degree of oversizing is necessary to allow the main aortic body to surround the chimney and to prevent the occurrence of gutters, which may cause type-1 endoleaks.